About this time Goethe interested himself in the study of Newton’s theory of colours, and, that he might understand it more fully, borrowed some prisms. When the owner asked that they should be returned, he thought he would like to try one of them again before sending them back. The result was that he began to suspect that Newton’s doctrine was not true, and in this suspicion he was confirmed by further research. This subject had an extraordinary fascination for Goethe, and almost to the end of his life he worked at it at intervals, firmly convinced, not only that Newton was wrong, but that he himself had discovered the true scientific significance of colours; and he attributed vast importance to his own doctrine. In old age he even told Eckermann one day that he did not at all pride himself on his poetry, but that his theory of colours did seem to him something to be proud of. Unfortunately, Goethe here dealt with problems for the solution of which he had not been adequately prepared. The subject appeared to him less complicated than it really is, and his conclusions have been unanimously rejected by men of science. His writings about it, however, have a certain interest, not merely because of their lucid style, but because he brings together much curious information relating to the history of opinion on the question, and also because it is hardly less instructive to understand the intellectual influences by which a great man is misled than to understand those by which he is guided to truth. In 1791 the Duke established a Court Theatre in Weimar, and asked Goethe to undertake the direction of it. Goethe consented, and for many years this was one of the duties to which he devoted most attention. His aim was to provide representations that should appeal to, and delight, a really cultivated taste, and he was almost as anxious that the acting should be maintained at a high level as that the dramas acted should be good. He took immense pains to realize his ideal, and under his control the Weimar Theatre ultimately became famous. All over Germany it was recognized as the theatre in which most was done for the development of a great school of dramatic art. The Duke, anxious to find some fitting way of expressing to Goethe his gratitude for the services he had rendered, presented him, in 1792, with the house in which he spent the rest of his life. Goethe changed it to suit his own ideas, and made it the handsomest and pleasantest private dwelling in Weimar. In altering it he received much help from his friend Meyer, the Swiss artist whose acquaintance he had made in Rome. Meyer had come to Weimar at Goethe’s urgent request, and for several years lived as a guest in his house. He painted for Goethe a portrait of Christiane with her little boy in her arms in the position of the “Madonna della sedia.” This portrait was always kept under a curtain, and Goethe counted it among the most precious of his treasures.